Method of producing granular surfactants

ABSTRACT

A process for the production of washing- and cleaning-active surfactant granules containing 60 to 70% by weight of surfactant and having an apparent density above 500 g/l, wherein a formulation containing a non-surface-active liquid component and having a liquid to paste-like form under normal pressure at temperatures of 20° to 40° C. is introduced to a fluidized bed and granulated and, at the same time, totally or partially freed from the non-surface-active liquid compound, optionally with addition of an inorganic or organic solid, and wherein the granules are discharged from the fluidized bed via a grading step by a countercurrent air-stream which is adjusted so that only particles above a predetermined size are removed from the granules.

FIELD OF THE INVENTION

This invention relates to a process for converting liquid to paste-likeformulations of washing- and cleaning-active surfactant compounds intostorable and dust-free granules of high apparent density.

STATEMENT OF RELATED ART

The economic synthesis of light-colored surfactant powders, moreparticularly anionic surfactants based on fatty alkyl sulfates ("FAS")and alkyl benzenesulfonates ("ABS"), is now established knowledge amongexperts. The corresponding surfactant salts are obtained aswater-containing products having water contents in the range from about20 to 80% by weight and, more particularly, around 35 to 60% by weight.Products of this type have a paste-like to cuttable consistency at roomtemperature, whereby the flowability and pumpability of such pastes islimited or lost at room temperature despite an active substance contentof only about 50% by weight, so that considerable problems arise in thestorage and subsequent processing of the pastes, particularly duringtheir incorporation in mixtures, for example in detergents. Accordingly,there has long been a need to provide detergent-quality surfactants in adry and, in particular, free-flowing form. Although free-flowingsurfactant powders, for example free-flowing FAS powders, can actuallybe obtained by conventional drying, for example in a spray drying tower,serious limitations have been observed in this regard, jeopardizingabove all the economy of using the powders thus obtained, particularlyFAS powders, on an industrial scale. Spray-dried FAS powder, forexample, has a very low apparent density, so that unprofitablecircumstances prevail in the packaging and marketing of these powdersor, alternatively, the powders have to be compacted by granulation torelatively heavy granules. However, even in the production of theso-called tower powders, safety considerations can necessitate suchrestricted operation of the spray drying process that practicaldifficulties arise. Thus, investigations into the safety aspects oftower powders based on FAS containing 20% by weight or more of activesubstance have shown that the spray drying of such formulations ispossible to only a very limited extent and, for example, requires towerentry temperatures below 200° C. Another disadvantage of spray dryinglies in the fact caking can occur in the tower and lead to browndiscoloration of the powder.

Comparable or other difficulties arise in the conversion of water-based,more particularly paste-like, formulations of many other washing- andcleaning-active surfactant compounds into storable solids. Furtherexamples of anionic oleochemical surfactant compounds are the knownsulfofatty acid methyl esters (fatty acid methyl ester sulfonates,"MES") which are produced by α-sulfonation of the methyl esters of fattyacids of vegetable or animal origin predominantly containing 10 to 20carbon atoms in the fatty acid molecule and subsequent neutralization towater-soluble monosalts, more particularly the corresponding alkalimetal salts. Ester cleavage thereof gives the corresponding sulfofattyacids or their disalts which have important washing and cleaningproperties in the same way as mixtures of disalts and sulfofatty acidmethyl ester monosalts. However, comparable problems also arise withother classes of surfactants when attempts are made to produce thecorresponding surface-active raw materials in dry form, as is the casewith cleaning-active alkyl glycoside compounds. To obtain fight-coloredreaction products, their synthesis generally has to be following bybleaching, for example with aqueous hydrogen peroxide, so that in thiscase, too, modern technology leads to the aqueous paste form.Water-containing alkyl glycoside pastes (APG pastes) are morevulnerable, for example, to hydrolysis or microbial contamination thancorresponding dry products. In their case, too, simple drying by knownmethods involves considerable difficulties. Finally, the drying of awater-containing paste of the alkali metal salts of washing-active soapsand/or of ABS pastes can also present considerable problems.

An alternative to the spray drying of surfactant pastes is granulation.Thus, European patent application EP 403 148 describes a process for theproduction of FAS granules which are dispersible in cold water. In thisprocess, a highly concentrated aqueous FAS paste containing less than14% by weight of water and less than 20% by weight of other additives ismechanically treated at temperatures of 10° to 45° C. until granules areformed. Although FAS granules dispersible at washing temperatures ofonly 4° to 30° C. are obtained in this way, the process temperatures tobe maintained and the relatively low maximum water content of thesurfactant paste do represent critical process parameters. In addition,the apparent densities of the granules obtained by this process are notmentioned.

European patent application EP 402 112 describes a process for theproduction of FAS and/or ABS granules comprising neutralization of theanionic surfactants in acid form to a paste containing at most 12% byweight of water with addition of auxiliaries, such as polyethyleneglycols, ethoxylated alcohols or alkylphenols having a melting pointabove 48° C., and granulation in a high-speed mixer. The quantity ofwater to be used is again a critical process parameter. In addition, theapparent densities of the surfactant granules obtained by this processare not mentioned.

European patent application EP 402 111 describes a process for theproduction of washing- and cleaning-active surfactant granules having anapparent density of 500 to 1200 g/l, in which a fine-particle solid isadded to a surfactant formulation which contains water as liquidcomponent and which may also contain organic polymers and builders andthe whole is granulated in a high-speed mixer. In this case, too, thewater content of the surfactant paste is a critical process parameter.If the water content of the surfactant paste is too high, the solid isdispersed so that it can no longer act as a deagglomerating agent. If,on the other hand, the solids content exceeds a certain value, themixture does not have the necessary consistency for granulation.

DETAILED DESCRIPTION OF THE INVENTION OBJECT OF THE INVENTION

The problem addressed by the present invention was to provide a processfor the production of heavy, free-flowing surfactant granules in whichthe presence of a non-surface-active liquid component would not be acritical process parameter.

SUMMARY OF THE INVENTION

Accordingly, the present invention relates to a process for theproduction of washing- and cleaning-active surfactant granules having anapparent density above 500 g/l by granulation of a surfactantformulation containing a non-surface-active liquid component, in which asurfactant formulation present in liquid to paste-like form under normalpressure at temperatures of 20° to 40° C. is granulated and at the sametime dried, optionally with addition of an inorganic or organic solid.

The process according to the invention has the advantage that it is notconfined to the production of granules of only a few surfactants, sothat free-flowing granules of anionic, nonionic, amphoteric, cationicsurfactants and mixtures thereof can be produced by this process, thecomposition of the granules being determinable in advance. Theproduction of anionic or nonionic surfactants or mixtures of anionicsurfactants and nonionic surfactants is preferred. In particular, theprocess according to the invention has advantages over spray dryingbecause granules containing nonionic surfactants, which are notaccessible to spray drying on account of their known pluming behavior,can also be produced by the process according to the invention. Inaddition, no browning of the granules occurs by virtue of the preferablyrelatively low process temperatures and the gentle drying conditions.

DESCRIPTION OF PREFERRED EMBODIMENTS

In a first embodiment, the surfactant formulation used in accordancewith the invention, which is present in liquid to paste-like form undernormal pressure at temperatures of 20° to 40° C., contains a mixture ofone or more surfactants and a non-surface-active liquid componentcontaining organic and/or inorganic constituents. In another embodiment,the surfactant formulation consists of at least two separate parts ofwhich the first contains a mixture of one or more surfactants and anon-surface-active liquid component containing organic and/or inorganicconstituents while the second or following parts either contain one ormore surfactants present in liquid to paste-like form under normalpressure at temperatures of 20° to 40° C., which are at least partlydifferent from the surfactants of the first part, or another mixture ofone or more surfactants, which are at least partly different from thesurfactants of the first part, and a non-surface-active liquid componentcontaining organic and/or inorganic constituents. In another embodimentof the invention, at least one constituent of the non-surface-activeliquid component is not incorporated in the above-mentionedsurfactant-containing parts of the surfactant formulation, but insteadis separately added. However, so far as the quantitative data (based onthe surfactant formulation) mentioned in the following are concerned, itis assumed that both the individual surfactant-containing parts of thesurfactant formulation and constituents of the non-surface-active liquidcomponent, which are added separately and not in the form of ahomogeneous mixture with surfactants, are optionally included in thesurfactant formulation.

The non-surface-active liquid component, which may contain one or moreconstituents, has a boiling point or rather a boiling range under normalpressure of preferably below 250° C. and, more preferably, below 200° C.In a particularly advantageous embodiment, the non-surface-active liquidcomponent contains constituents which boil at 60° to 180° C. undernormal pressure. Monohydric and/or polyhydric alcohols, for examplemethanol, ethanol, propanol, isopropanol, butanol, secondary andtertiary butanol, pentanol, ethylene glycol, propane-1,2-diol, glycerolor mixtures thereof are preferably added as the organic constituentoptionally present in the non-surface-active liquid component. Thepercentage content of the mono- and/or polyhydric alcohols used as thenon-surface-active liquid component is preferably 0.5 to 10% by weight,based on the surfactant formulation.

However, it is particularly preferred to use water, optionally togetherwith such organic constituents as ethanol, propane-1,2-diol or glycerol,as the inorganic constituent of the non-surface-active liquid component.In this case, the percentage content of water is preferably from 25 to80% by weight, based on the surfactant formulation. The total percentagecontent of the non-surface-active liquid component is preferably between30 and 70% by weight and, more preferably, between 45 and 60% by weight,based on the surfactant formulation.

The anionic surfactants used are, for example, anionic surfactants ofthe sulfonate and sulfate type. Preferred surfactants of the sulfonatetype are C₉₋₁₃ alkyl benzenesulfonates, olefin sulfonates, i.e. mixturesof alkene and hydroxyalkane sulfonates, and also disulfonates of thetype obtained, for example, from C₁₂₋₁₈ monoolefins with a terminal andinternal double bond by sulfonation with gaseous sulfur trioxide andsubsequent alkaline or acidic hydrolysis of the sulfonation products.Also suitable are alkane sulfonates of the type obtainable from C₁₂₋₁₈alkanes by sulfochlorination or sulfoxidation and subsequent hydrolysisor neutralization. In particular, esters of α-sulfofatty acids (estersulfonates) which are produced by α-sulfonation of the methyl esters offatty acids of vegetable and/or animal origin containing 10 to 20 carbonatoms in the fatty acid molecule and subsequent neutralization towater-soluble monosalts, for example the α-sulfonated methyl esters ofhydrogenated coconut oil, palm kernel oil or tallow fatty acids, andalso the α-sulfofatty acids obtainable by ester cleavage and disaltsthereof am produced by the process according to the invention. Theproduction of mixtures of the monosalts and disalts with othersurfactants, for example with alkyl benzenesulfonates, is alsopreferred.

Suitable surfactants of the sulfate type are the sulfuric acidmonoesters of primary alcohols of natural and synthetic origin, moreparticularly of fatty alcohols, for example coconut oil fatty alcohols,tallow fatty alcohols, oleyl alcohol, lauryl alcohol, myristyl alcohol,palmityl alcohol or stearyl alcohol, or the C₁₀₋₂₀ oxoalcohols and thoseof secondary alcohols having the same chain length. Sulfuric acidmonoesters of the alcohols ethoxylated with 1 to 6 moles of ethyleneoxide, such as 2-methyl-branched C₉₋₁₁ alcohols containing on average3.5 moles of ethylene oxide, are also suitable, as are sulfated fattyacid monoglycerides. However, the production of surfactant granulescontaining C₁₂₋₁₈ alkyl sulfates (FAS) or C₁₆₋₁₈ alkyl sulfates (TAS)either on their own or together with other surfactants is particularlypreferred.

Other anionic surfactants which may be produced in granular form by theprocess according to the invention are soaps of natural or synthetic,preferably saturated or ethylenically unsaturated fatty acids. Soapmixtures derived from natural fatty acids, for example coconut oil, palmkernel oil or tallow fatty acids, are particularly suitable. Soapmixtures of which 50 to 100% consist of saturated C₁₂₋₁₈ fatty acidsoaps and 0 to 50% of oleic acid soaps are preferred. Granulescontaining soap blended with other surfactants are preferably producedby the process according to the invention.

The anionic surfactants may be used in the form of their sodium,potassium, calcium and ammonium salts and also as water-soluble salts oforganic bases, such as monoethanolamine, diethanolamine ortriethanolamine. They are preferably used in the form of aqueouspreparations, more particularly in the form of about 30 to 60% by weightaqueous preparations in which the anionic surfactants accumulate duringtheir production by neutralization of the corresponding acids.

Granules produced by the process according to the invention preferablycontain nonionic surfactants, more particularly together with anionicsurfactants, for example alkyl benzenesulfonate and/or fatty alkylsulfate. The nonionic surfactants are preferably derived from liquidethoxylated, more particularly primary, alcohols preferably containing 9to 18 carbon atoms and, on average, 1 to 12 moles of ethylene oxide permole of alcohol, in which the alcohol radical may be linear ormethyl-branched in the 2 position or may contain a mixture of linear andmethyl-branched radicals such as is normally present in oxoalcoholradicals. However, linear radicals of C₁₂₋₁₈ alcohols of natural origin,for example coconut oil alcohol, tallow fatty alcohol or oleyl alcohol,are particularly preferred. The degrees of ethoxylation mentioned arestatistical mean values which, for a specific product, may be a wholenumber or a mixed number. Preferred alcohol ethoxylates are theso-called narrow-range ethoxylates ("NRE"). Alcohol ethoxylatescontaining on average 2 to 8 ethylene oxide groups are particularlypreferred. Preferred ethoxylated alcohols include, for example, C₉₋₁₁oxoalcohol containing 7 EO, C₁₃₋₁₅ oxoalcohol containing 3 EO, 5 EO or 7EO and, more particularly, C₁₂₋₁₄ alcohol containing 3 EO or 4 EO,C₁₂₋₁₈ alcohols containing 3 EO, 5 EO or 7 EO and mixtures thereof, suchas mixtures of C₁₂₋₁₄ alcohol containing 3 EO and C₁₂₋₁₈ alcoholcontaining 5 EO.

In addition, the granules produced by the process according to theinvention may contain as nonionic surfactants alkyl glycosidescorresponding to the general formula R--O--(G)_(x), in which R is aprimary linear or 2-methyl-branched aliphatic radical containing 8 to 22and preferably 12 to 18 carbon atoms, G is a symbol which stands for aglycose unit containing 5 or 6 carbon atoms and the degree ofoligomerization x is between 1 and 10, preferably between 1 and 2 and,more preferably, is distinctly smaller than 1.4.

The percentage content of the surfactants in the surfactant formulationas a whole is preferably between 20 and 75% by weight and morepreferably between 35 and 70% by weight.

The surfactant formulation preferably contains as further constituentsadditives which are ingredients of detergents and cleaning products.Surfactant formulations containing additives in quantities of 0.001 to15% by weight, based on the surfactant formulation as a whole, arepreferably used in the process according to the invention. Particularlypreferred additives are dyes, foam inhibitors, bleaches and/orsolubility-improving constituents.

Suitable dyes are heat-stable dyes, preferably pigments, which areadvantageously used in quantities of 0.001 to 0.5% by weight, based onthe surfactant formulation.

Suitable foam inhibitors are, for example, soaps of natural andsynthetic origin which have a high percentage content of C₁₈₋₂₄ fattyacids. Suitable non-surface-active foam inhibitors areorganopolysiloxanes and mixtures thereof with microfine, optionallysilanized silica, paraffins, waxes, microcrystalline waxes and mixturesthereof with silanized silica. Bis-acylamides derived from C₁₂₋₂₀ alkylamines and C₂₋₆ dicarboxylic acids may also be used. Mixtures ofdifferent foam inhibitors, for example foam inhibitors of silicones andparaffins or waxes, may also be used with advantage. The foam inhibitorsare preferably fixed to a granular carrier material soluble ordispersible in water. The content of foam inhibitors in the surfactantformulation is preferably between 0.01 and 0.5% by weight.

Among the compounds yielding H₂ O₂ in water which serve as bleaches,sodium perborate tetrahydrate and sodium perborate monohydrate areparticularly important. Other useful bleaches are, for example,peroxycarbonate, peroxypyrophosphates, citrate perhydrates,peroxyphthalates, diperazelaic acid or diperdodecanedioic acid. Inparticular, hydrogen peroxide is also preferably used as bleach in thesurfactant formulations used in accordance with the invention. Thebleach content of the surfactant formulations is preferably from 0.5 to15% by weight. More particularly, the hydrogen peroxide content is from0.5 to 5% by weight.

Solubility-improving constituents include liquid, paste-form and solidcompounds which are soluble or dispersible in the other constituents ofthe surfactant formulation. Polyethylene glycols having a relativemolecular weight of 200 to 20,000 and highly ethoxylated fatty alcoholscontaining 14 to 80 ethylene oxide groups per molecule, moreparticularly C₁₂₋₁₈ fatty alcohols containing 20 to 60 ethylene oxidegroups, for example tallow fatty alcohol containing 30 EO or 40 EO, arepreferably used as the solubility-improving constituents. It isparticularly preferred to use polyethylene glycols having a relativemolecular weight of 200 to 600. These polyethylene glycols areadvantageously used as a separate constituent of the non-surface-activeliquid component. The percentage content of these constituents, whichimprove the solubility of the granules, in the surfactant formulation ispreferably from 1 to 15% by weight and, more preferably, from 2 to 10%by weight.

The surfactant formulation is granulated and dried at one and the sametime. By "drying" is meant the partial or complete removal of thenon-surface-active liquid component. If desired, residues of free, i.e.unbound, water and/or monohydric and/or polyhydric alcohols may bepresent as long as the granules remain free-flowing and non-tacky.However, the free water content preferably does not exceed 10% by weightand, more preferably, does not exceed 0.1 to 2% by weight, based on thefinal granules.

According to the invention, the surfactant granules may be produced inany machines in which granulation and drying can be carried out at oneand the same time. Examples of such machines are heatable mixers andgranulators, more particularly granulators of the Turbo Dryer® type(manufacturer: Vomm, Italy). In one preferred embodiment of theinvention, however, the steps of granulation and drying are carried outtogether in a batch-type or continuous fluidized bed. In a particularlypreferred embodiment, the process is carried out continuously in afluidized bed. To this end, the surfactant formulation or the individualconstituents of the surfactant formulation may be introduced into thefluidized bed simultaneously or successively through a single nozzle,for example a multiple-bore nozzle, or through several nozzles. However,it is also possible simultaneously and separately to add a constituentof the non-surface-active liquid component which was not incorporated inthe surfactant formulation. The nozzle or nozzles and spraying directionfor the products to be sprayed may be arranged in any way. Preferredfluidized bed machines have base plates measuring at least 0.4 m.Particularly preferred fluidized beds have a base plate from 0.4 to 5 min diameter, for example 1.2 m or 2.5 m in diameter. However, fluidizedbeds having a base plate larger than 5 m in diameter are also suitable.The base plate used is preferably a perforated plate or a so-calledConidur plate (a product of Hein & Lehmann, Federal Republic ofGermany). The process according to the invention is preferably carriedout at flow rates of the fluidizing air of 1 to 8 m/s and, moreparticularly, 1.5 to 5.5 m/s. The granules are advantageously dischargedfrom the fluidized bed via a grading stage. Grading may be carried out,for example, by means of a sieve or by a countercurrent air stream(sizing air) which is adjusted in such a way that only particles beyonda certain size are removed from the fluidized bed while smallerparticles are retained therein. In one preferred embodiment, thein-flowing air is made up of the heated or unheated sizing air and theheated base air. The temperature of the air at the base plate ispreferably between 80° and 400° C. and, more preferably, between 90° and350° C. The fluidizing air is cooled by heat loss and by the heat ofevaporation of the constituents of the non-surface-active liquidcomponent. In one particularly preferred embodiment, the temperature ofthe fluidizing air about 5 cm above the base plate is 60° to 120° C.,preferably 65° to 90° C. and, more preferably, 70° to 85° C. The airexit temperature is preferably between 60° and 120° C., moreparticularly below 100° C. and, with particular advantage, between 70°and 85° C. In the preferred fluidized-bed process, a starting materialserving as initial carrier for the surfactant formulation sprayed inmust be present at the beginning of the process. Suitable startingmaterials are, above all, ingredients of detergents, more particularlythose which may also be used as solids in the process according to theinvention and which have a particle size distribution substantiallycorresponding to the particle size distribution of the final granules.In a particularly preferred embodiment, however, surfactant granulesobtained in a previous run of the process are used as the startingmaterial.

In the fluidized bed, the constituents of the non-surface-active liquidcomponent undergo complete or partial evaporation. Partially dried tofully dried nuclei are formed and are coated with further quantities ofthe surfactant formulation introduced, granulated and, at the same time,dried.

In one particularly important embodiment, the formulation is granulatedand, at the same time, dried with addition of an inorganic or organicsolid which may be pneumatically introduced through blow pipes. Thissolid, which serves as carrier for the surfactant formulation,preferably consists of ingredients of detergents. Suitable solids are,for example, surfactants and surfactant mixtures which have beenproduced by granulation, by spray drying or by the process according tothe invention and which are recycled to increase the surfactantconcentration in the final granules. It is particularly preferred to usespray-dried surfactant granules and/or surfactant granules obtained bythe process according to the invention. Highly ethoxylated fattyalcohols, for example containing 20 to 80 EO and preferably 20 to 60 EO,more particularly tallow fatty alcohol containing 30 or 40 EO, may alsobe used with advantage as solids as an alternative to incorporation inthe surfactant formulation.

In another preferred embodiment, the solids used are non-surface-activeingredients of detergents and cleaning preparations, preferably one ormore constituents from the group consisting of alkali metal carbonates,alkali metal sulfates, crystalline and amorphous alkali metal silicatesand layer silicates and also zeolites, more particularlydetergent-quality zeolite NaA, salts of citric acid, solid peroxybleaches and, optionally, bleach activators and solid polyethyleneglycols having a relative molecular weight of, or more than, 2000, moreparticularly between 4000 and 20,000.

The solids used are preferably fine-particle materials which can eitherbe directly produced or purchased as such or which may be convened intothe fine-particle state by standard methods of size reduction, forexample by grinding in typical mills. Preferred solids contain, forexample, no more than 5% by weight of particles larger than 2 mm indiameter and preferably no more than 5% by weight of particles largerthan 1.6 mm in diameter. Solids of which at least 90% by weight consistof particles smaller than 1.0 mm in diameter are particularly preferred.Examples of such solids are alkali metal carbonates containing more than90% by weight of particles 0.5 mm or smaller in diameter anddetergent-quality zeolite NaA powder containing at least 90% by weightparticles smaller than 0.03 mm in diameter. In a particularlyadvantageous embodiment, the solids added are used in quantities of 10to 50% by weight and, more particularly, in quantities of 20 to 45% byweight, based on the sum total of surfactant formulation and solid.

In another preferred embodiment, the invention relates to surfactantgranules produced by the process according to the invention. Preferredsurfactant granules contain from 10 to 100% by weight, more preferablyfrom 30 to 80% by weight and, with particular advantage, from 40 to 70%by weight of surfactants, based on the final granules. Pure surfactantgranules are obtained if the non-surface-active liquid component iscompletely evaporated so that the granules are completely dried and thesolid optionally added consists of a pure surfactant material. In thiscase, surfactant granules produced by the process according to theinvention and used as solid in the process according to the inventionare optionally size-reduced to the required particle size distributionand recycled. The surfactant content of the granules may be adjusted toany of the required values.

The surfactant granules obtained by the process according to theinvention preferably have an apparent density of 550 to 1000 g/l and,more preferably, 550 to 850 g/l and are dust-free, i.e. they contain noparticles smaller than 50 μm in size. The particle size distribution ofthe surfactant granules otherwise corresponds to the typical particlesize distribution of a heavy state-of-the-an detergent. Moreparticularly, (he surfactant granules have a particle size distributionin which at most 5% by weight and preferably at most 3% by weight of theparticles are larger than 2.5 mm in diameter and at most 5% by weightand, with particular advantage, at most 3% by weight of the particlesare below 0.1 mm in diameter. The surfactant granules are distinguishedby their light color and by their flowability. No further measures needbe taken to prevent the surfactant granules produced in accordance withthe invention from adhering to one another. If desired, however, theprocess according to the invention may be followed by an additional stepin which the surfactant granules are dusted in known manner withfine-particle materials, for example with zeolite NaA or soda, in orderfurther to increase their apparent density. This dusting or powderingmay be carried out, for example, during a rounding step. However,preferred surfactant granules already have such a regular and, inparticular, substantially spherical structure that a rounding step isgenerally unnecessary and, hence, is also not preferred.

EXAMPLES

In Examples 1 to 10, a surfactant formulation which could consist of oneor more separate parts was granulated and, at the same time, driedtogether with a solid via a nozzle in a combined granulating and dryingmachine (manufacturer: Glatt, Federal Republic of Germany). The startingmaterial used consisted of surfactant granules which had been obtainedin a preceding batch (under the same process conditions) and which hadsubstantially the same composition as the final granules of Examples 1to 10. The process conditions are shown in Table 1.

The following substances were used in the surfactant formulation:

    ______________________________________                                        Sulfopon ® T 55                                                                      containing 54% by weight of tallow fatty                                      alcohol sulfate and about 41% by weight of                                    water (a product of Henkel KGaA)                                   Texapon ® LS 35                                                                      containing 34% by weight of C.sub.12-14 fatty                                 alcohol sulfate and about 64% by weight of                                    water (a product of Henkel KGaA)                                   Dehydrol ® LT 7                                                                      containing 99% by weight of C.sub.12-18 fatty                                 alcohol.7 EO (a product of Henkel KGaA)                            Texin ® ES 68                                                                        containg 53% by weight of sodium monosalt of                                  tallow fatty acid methyl ester, 11% by weight                                 of disodium salt of sulfotallow fatty acid and                                about 33% by weight of water (a product of                                    Henkel KGaA)                                                       PEG 400    polyethylene glycol having a relative                                         molecular weight of 400.                                           ______________________________________                                    

These constituents were introduced separately and simultaneously intothe fluidized bed through a nozzle.

The following solids were used:

    ______________________________________                                        Soda      sodium carbonate having an apparent density of                                620 g/l (a product of Matthes & Weber, Federal                                Republic of Germany)                                                Wessalith ® P                                                                       zeolite powder (a product of Degussa, Federal                                 Republic of Germany)                                                Carrier bead                                                                            zeolite granules containing 67% by weight                                     zeolite (counted as anhydrous), 11% by weight                                 of a polymeric polyacrylate, 1.85% by weight of                               tallow fatty alcohol.5 EO, 2% by weight sodium                                sulfate and 17% by weight of water                                  Citrate trisodium citrate EP powder (dihydrate, a product of                  Jungbunzlauer, Federal Republic of Germany)                                   Sulfopon ® T                                                                        tallow fatty alcohol sulfate powder (a product                                of Henkel KGaA)                                                     B 5       ground product of Example 5 (particle size                                    distribution same as Sulfopon ® T)                              ______________________________________                                    

Dust-free non-tacky granules of high surfactant content were obtained inall the Examples (see Table 2). The percentage content of granuleslarger than 2.5 mm in size was below 5% by weight in all the Examples.

                                      TABLE 1                                     __________________________________________________________________________    Process parameters                                                                           Examples                                                                      1   2   3    4   5   6   7   8   9   10                        __________________________________________________________________________    Fluidized bed                                                                 diameter in mm 400 1200                                                                              1200 400 400 400 400 400 400 400                       surface area in m.sup.2                                                                      0.13                                                                              0.13                                                                              0.13 0.13                                                                              0.13                                                                              0.13                                                                              0.13                                                                              0.13                                                                              0.13                                                                              0.13                      Fluidizing air flow rate in m/s                                                              5.1 2.35                                                                              2.62 2.8 2.6 2.6 2.7 2.6 2.6 2.6                       (under operating conditions)                                                  Temperatures in °C.                                                    air at base plate                                                                            100 126 175  132 137 137 150 130 160 160                       grading air    20  20  20   20  20  20  20  20  20  20                        fluidizing air about 5 cm                                                                    81  82  82   77  75  82  89  78  80  76                        above the base plate                                                          air exit       76  76  77   73  71  75  82  70  73  71                        Air flow in m.sup.3 /h                                                                       2341                                                                              9563                                                                              10685                                                                              1300                                                                              1180                                                                              1180                                                                              1220                                                                              1180                                                                              1190                                                                              1190                      (under operating conditions)                                                  Air loading (g H.sub.2 O/kg air)                                                             3.8 10.8                                                                              31.2 11  12  9.3 9.0 11  14  13                        Throughput of sufactant                                                       formulation in kg/h                                                           Sulfopon ® T 55                                                                          20  180 520  28  42  33  33  40  50  --                        Texapon ® LS 35                                                                          --  --  --   10  --  --  --  --  --  --                        Dehydol ® LT 7                                                                           --  --  --   --  --  --  --  3   --  --                        Texin ®ES 68                                                                             --  --  --   --  --  --  --  --  --  30                        PEG 400        --  --  --   --  --  3   --  --  --  --                        Throughput of solids in kg/h                                                                 12  60  370  19  --  --  5.4 --  --  --                        Wessalith ® P                                                                            --  --  --   --  --  --  13.6                                                                              --  --  --                        Carrier bead   --  --  --   --  --  --  --  --  --  25                        Citrate        --  --  --   --  --  --  --  --  15  --                        Sulfopon  ® T                                                                            --  --  --   --  20  --  --  20  --  --                        B 5            --  --  --   --  --  19  --  --  --  --                        Starting material in kg                                                                      25  120 120  20  20  20  20  20  20  20                        __________________________________________________________________________

                                      TABLE 2                                     __________________________________________________________________________    Characteristic data of the products                                                          Examples                                                                      1  2  3  4  5  6  7  8  9  10                                  __________________________________________________________________________    Total surfactant content in                                                                  45.5                                                                             66.0                                                                             45.7                                                                             47 87 83 46 80.2                                                                             56.8                                                                             29.3                                % by weight                                                                   Water content in % by weight                                                                 <1 <1 <1 <1 <1 <1 7.2*                                                                             <1 4.8                                                                              <1                                  Apparent density in g/l                                                                      790                                                                              615                                                                              580                                                                              630                                                                              512                                                                              540                                                                              655                                                                              505                                                                              675                                                                              685                                 Sieve analysis in % by weight                                                    2.5 mm      -- -- 1.9                                                                              -- -- -- -- -- -- --                                     1.6 mm      97.2                                                                             6.1                                                                              17.1                                                                             9.8                                                                              24.9                                                                             27.0                                                                             0.3                                                                              13.1                                                                             0.7                                                                              4.8                                    0.8 mm      2.8                                                                              6.2                                                                              14.0                                                                             44.4                                                                             72.8                                                                             64.0                                                                             38.1                                                                             86.0                                                                             51.3                                                                             23.0                                   0.6 mm      0.0                                                                              7.9                                                                              57.7                                                                             23.6                                                                             1.0                                                                              5.4                                                                              48.4                                                                             0.8                                                                              38.6                                                                             14.7                                   0.4 mm      -- 23.7                                                                             8.4                                                                              16.4                                                                             0.6                                                                              2.8                                                                              12.0                                                                             0.1                                                                              8.6                                                                              18.7                                   0.2 mm      -- 40.2                                                                             0.9                                                                              4.8                                                                              0.4                                                                              0.6                                                                              0.9                                                                              -- 0.6                                                                              22.0                                   0.1 mm      -- 14.0                                                                             -- 1.0                                                                              0.3                                                                              0.2                                                                              0.2                                                                              -- 0.2                                                                              14.3                                  0.05 mm      -- 1.8                                                                              -- -- -- -- 0.1                                                                              -- -- 2.5                                 <0.05 mm       -- -- -- -- -- -- -- -- -- --                                  __________________________________________________________________________     *Including water from zeolite                                            

The invention claimed is:
 1. A process for the production of washing-and cleaning-active surfactant granules, wherein said granules areprepared from a composition consisting of 40 to 70% by weight ofsurfactant and reciprocally 60-30% by weight of a non-surface-activeliquid component, and having a liquid to paste-like form under normalpressure at temperatures of 20° to 40° C., said composition beingintroduced to a fluidized bed and granulated and, at the same time,totally or partially freed from the non-surface-active liquid component,optionally with addition of: (a) 0.5 to 10% by weight, based on thesurfactant composition, of mono- or polyhydric alcohols, (b) 0.001 to15% by weight, based on the surfactant composition, of dyes or foaminhibitors, and (c) 10 to 50% by weight, based on the sum total ofsurfactant composition and solid, of solid additives selected from thegroup consisting of alkali metal carbonates, alkali metal sulfates,zeolite, salts of citric acid, peroxy bleaches, bleach activators,polyethylene glycols having a relative molecular weight in the rangefrom 4000 to 20,000 and ethoxylated fatty alcohols containing 20 to 80ethylene oxide groups to the surfactant composition, and wherein thegranules are discharged from the fluidized bed via a grading step by acountercurrent air-stream which is adjusted so that only particlessmaller than 50 μm in size are removed from the granules, said granuleshaving an apparent density above 500 g/l.
 2. A process as claimed inclaim 1, wherein the surfactant composition consists of surfactants orsurfactant mixtures selected from the group consisting of fatty alkylsulfates, C₉ -C₁₃ alkyl benzenesulfonates and sulfofatty acid methylesters, and liquid ethoxylated fatty alcohols containing 2 to 8 ethyleneoxide groups per molecule.
 3. A process as claimed in claim 1 whereinthe surfactant composition consists of at least two separate parts ofwhich the first contains a mixture of one or more surfactants and anon-surface-active liquid component while the second or following partseither contain one or more surfactants present in liquid to paste-likeform under normal pressure at temperatures of 0° to 40° C., which are atleast partly different from the surfactants of the first part, oranother mixture of one or more surfactants, which are at least partlydifferent from the surfactants of the first part, and anon-surface-active liquid component.
 4. A process as claimed in claim 1,wherein the non-surface-active liquid component boils between 60° and180° C. under normal pressure.
 5. A process as claimed in claim 4wherein water is used as the non-surface-active liquid component.
 6. Aprocess as claimed in claim 1, wherein the surfactant compositionconsisting of said surfactant and said non-surface-active liquidcomponent is dried and, at the same time, totally or partially freedfrom the non-surface-active liquid component in a fluidized bed eitherin batches or continuously, the fluidized bed being fluidized by flowingair.
 7. A process as claimed in claim 6, wherein the surfactantcomposition or individual parts of the surfactant composition aresimultaneously or successively introduced into the fluidized bed througha single nozzle or through several nozzles.
 8. A process as claimed inclaim 6, wherein the fluidizing air flows at a rate between 1.5 and 5.5m/s.
 9. A process as claimed in claim 6, wherein the fluidized bed isformed in a machine with a base plate, the air temperature at the baseplate is between 90° and 350° C.; the temperature of the fluidizing airabout 5 cm above the base plate is between 65° and 90° C.; and the airexit temperature is between 60° and 100° C.